China's modernization is often celebrated by images of progress: gleaming new skyscrapers, bullet trains, and a rising middle class. But since 2006, photographer Ian Teh has been exploring what he calls the undercurrents of China’s economic and industrial progress, especially the country’s rapid environmental degradation.

On the eve of Earth Day this spring, MSNBC.com published “Yellow River: China’s environmental sorrow,” a version of Teh’s project about the ecological and esthetic demise of the Yellow River. The work is a beautiful lament. Presented as a video slideshow with a voiceover narrative read by Teh, the (mostly) panoramic images evoke not only a sense of loss, but also a willfulness to forget.

“It was important to me, for most of the images, that the first impression of these landscapes was one of beauty. This aspect of the experience, I felt, connected the viewer to the reverence the Chinese had accorded to the great river throughout history,” Teh explains in an e-mail interview.

He adds that he also wanted to create a sense of ambiguity within the images. “This was important because embedded within many of the images were subtle signs of the transactional costs incurred in the realization of China’s dream to modernize … What I hope the viewer will take away is a bittersweet experience, a sense of what could ultimately be an irretrievable loss.”

Teh has worked on a number of stories about China with MSNBC.com Director of Photography Amy Pereira over the last decade. She has kept tabs on the development of Teh’s Yellow River project since he started it in 2011, and has been waiting for the right time to publish it.

“It’s a good fit for MSNBC.com because it covers many of the issues we focus on, including socioeconomic disparity and the environment,” Pereira says via e-mail.

“So much great work has come out of China in recent years, but Ian has a unique eye and keen understanding of these issues from years of concentrated focus,” she says, adding, “His photos possess a great deal of humanity, depth and beauty.”

Teh began exploring the environmental costs of China’s modernization after moving to Beijing in 2006. With so many journalists doing stories about the manifestations of China’s economic growth, he decided to explore its less visible roots. Energy production struck him as an obvious place to start. China was building an average of two coal power stations per week when he arrived; the rate has since doubled.

“I decided to explore the coal industry,” he explains. The result was “Dark Clouds,” a series of bleak, artful, documentary images of coalburning operations and the people who work in them. As an extension of that project, he did a series called “Traces,” featuring panoramics of landscapes altered by coal and other types of industrial production.

Teh explained that the “Traces” project led him to consider how societies tend to take stock of their environments only periodically. They notice incremental change only when “something significant has happened to mark that change—for example a demolition, the beginning of an enormous construction, or the completion of a new building or engineering project,” he says.

But China has been altering its natural environment at what he terms “a rapacious pace” for three decades. Teh wanted to document those changes with the intent “to engage contemplation” about them. His ongoing Yellow River project is part of that effort.

He started the project in Lanzhou in 2011, after receiving a Magnum Foundation Emergency Fund grant. He chose Lanzhou because it was the first city built on the river and remains the largest. The area around Lanzhou is “known as China’s cradle of civilization, one that dates back some 5,000 years,” Teh says. “Today, it’s a fast-growing city, a petrochemical hub and one of the most polluted cities in China.”

At the outset he consulted maps and researched both print and online resources to gain an understanding of the river from historical, environmental, economic and political perspectives. “What was important for me was to get an overview on the river and the places I was planning to visit. Once I had decided where I was going, the rest of it was about exploring on the ground and seeing what I discovered.”

Teh does a lot of driving and walking in search of images. “The area that I am exploring is vast, while my budget is limited,” he says. “Patience and persistence are friends.”

As part of his “Traces” project, the Yellow River project emphasizes panoramic landscapes. The scale of a panoramic image “is an important part of the viewer experience,” particularly in exhibition settings, he explains. But he also shoots with a 35mm camera for images that provide context and show the region on “a more human scale.”

The portraits and images of everyday realities of peoples’ lives “serve as reminders that these sometimes beautiful landscapes are places where people have to live and work, and that there is another narrative that isn’t fully revealed,” he explains, adding, “The people are there [in several images] to humanize the landscape.”

On the surface, the images are spare, simple, and beautiful. But Teh is most interested in finding images that have other layers of significance, even though that significance may not be immediately apparent. One of Teh’s favorite images is a bird’s-eye view of the Yellow River.

“Nothing is in the image other than the sunlit ripples of the river’s water. It suggests something otherworldly and sublime, peaceful,” he says. “I’m afforded that view because of the dam I’m standing on, China’s first dam and an engineering feat of the ‘60s, but its construction was fraught with problems and controversy.” (Teh notes that his extended captions, which offer information outside the context of the frame, are an integral part of each image.)

Pereira suggested to Teh the idea of publishing the images on MSNBC.com as a narrated video.

“We’ve been experimenting with different approaches to storytelling since we launched in the fall,” she says. “There is such grace to Ian’s photographs and they lend themselves beautifully to the fluidity of film.”

Although Teh narrates the video, he was reluctant to write the voiceover script. “I wanted the narration to have a more lyrical presence that matched the mood of the images, and so I suggested E. J. Swift,” the science fiction and fantasy writer, he says.

In addition to publication by MSNBC.com, Teh’s Yellow River project was exhibited at Open Society Foundations’ Moving Walls 2013. As he continues to work on the project, he’s looking for other exhibition venues, including in China.